Strongarm may be employed to protect neighbourhoods or to raid those of enemies (see below). Paying a strongarm gang to protect a neighbourhood means that if it is attacked by other families then the strongarms will fight against the raiders. This prevents mafia Family members being killed and can offer better protection.
There are two types of raid: either the police may raid an institution belonging to a Family, or one Family may instigate a raid on the property of another.
The police's actions are determined randomly. If you have bribed the police in your area (i.e. Manhattan, Queens, Bronx, Brooklyn or Staten Island) then you are immune from raids on your institutions. Otherwise each institution has a 10% chance per round of being raided. If it is raided the institution will not generate any revenue that round and there's a 25% chance that a Family member will be arrested and imprisoned for three rounds.
A Family may either personally raid an institution or they may send strongarms there to do it for them. If it's in a neighbourhood protected by strongarm then the strongarms will do the fighting, otherwise it's the mafia Family who have to put up members to do the protection. To do a raid, the Don must write orders for the B-round, specifying the institution to be raided and who will be sent to do the raiding. The target Family will be informed where they'll be raided (though not given any details of who's attacking) and must give instructions about who will protect the joint.
If the raid turns out to be strongarm-vs-strongarm then the combat is decided at the end of the B-round without acting. Otherwise it's decided by acting (see combat section).
A successful raid means that all the revenue from that institution will go to the attacking Family that round.